net: mscc: ocelot: add a new ocelot_vcap_block_find_filter_by_id function

And rename the existing find to ocelot_vcap_block_find_filter_by_index.
The index is the position in the TCAM, and the id is the flow cookie
given by tc.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>